Circuit-interrupter.



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UNITED STATES PATENT oPPICE.

JOSEPH N. MAPIoNEY, 0E WILKINSBUEQAND WALTER M. AUSTIN, or sWIssvALE,PENNSYLVANIA, AssIGNoNs To WESTINGPIOUSE ELECTRIC AND MANUFACTURINGCOMPANY, A CoIiPoRATIoN or PENNSYLVANIA.

CIRCUIT-INTERRUPTER.

Specification of Letters Patent.

Patented July 4, 1916.

Application filed September 28, 1912. Serial No. 722,933.

' providejaia,l device of the above indicated charl ,t1- shall be simpleand durable in construction,-leifective and reliable inv operation aeterand that shall embody coperating main contact members and a plurality ofsets of auxiliary Contact terminals to be disengaged successively duringthe opening operation of the interrupter in order that the final inter-Yruption of the circuit shall be confined to the carbon arcing terminals.

Another object of our invention is to provide a circuit interrupter inwhich the carbon contact terminals are so constructed and arranged, withrespect to the main contact members and otherauxiliarycontact.terminals, as to be maintained in cooperativeengagement during a portion of the opening operation of the interrupterto permit the separation of the other coperating Contact members andterminals to a suilicieiit degree to obviate the possibility ofrestablishing the circuit through an are which might be formed when theinterrupter is finally opened.

Another object is to make provision for effecting a sliding or wipingaction between the carbon terminals so that they may be kept free fromdirt and a. good electrical contact may be secured, and a further obJectis to mount the carbon terminals so that they will be sel-alining. v

A still further object of our invention is to provide the auxiliarycarbon .arcing terminals with conducting plates which are adapted toycooperatively engage one another and which are electrically connected tothe main Contact terminals by means of flexible contact membeis, therebyinsuring a connection of relatively good electrical conductivity inshunt'to the main contact members. y

A still further object of our invention is to provide a set ofintermediate auxiliary contact terminals in multiple relation to themain Contact members which are so arranged and 'constructed as tocoperatively engage one another with any predetermined pressure at theinstant that their engagement is eected. Moreover, these intermediatecontact terminals are adapted to be brought into engagement with asliding or wiping motion which serves to clean the contact surfaces.Furthermore, the disposition of the intermediate contact terminals andtheir Supporting means is such as to relieve the supporting f' meansfromany undue strain or tendency-to buckle wliici might otherwise becaused in case of any slight roughness upon the cooperating Contactsurfaces of the contact terminals.

Our invention may be best understood by 'reference to the accompanyingdrawing, in

which- Figure 1 is a View in side elevation of a portion of a circuitinterrupter constructed in accordance with our invention, Fig. 2 is aview iii front elevation of aportion of the mechanism shown in Fig. 1,the movable carbon terminal and its supporting arm being removed for thesake of clearness. Fig. 3 is a detail view, in side elevation, of theretaining member shown in Figs. 1 and 2, and Figs. A and 5 are outlineviews of the coperating-carbon arcing terminals show-n in Figs. 1 and 2,illustrating the positions of'v the terminals and their associated partsduring two successive stages in the opening operation of theinterrupter.

Referring to the drawing, the device here shown comprises an insulatingpanel, 1, a main stationary contact member 2, a movable coperatingcontact member 3, a plurality of carbon arcing terminals l and 5 havingcooperating contact plates 6 and 7, a supporting linkage 8 ior thecarbon terminal Il, a supporting arm 9 for the carbon terminal 5, astationary intermediate terminal 10 and a movable resiliently supportedContact terminal 11 to coperatc therewith.

The main contact member 2 constitutes a block having an integral stud 12which projects through tlie insulating panel 1 and is suitably securedthereto, and the movable contact member 3 is of well-known constructionand comprises a plurality of lamiii 13 of conducting material which areassembled in the form-of a. bridging brush and are suitably secured to asupporting arm 14. rlhe supporting arms 9 and 14 may `be pivotallymounted upon portions of the supporting structure (not shown) and may beoperatively associated, the one with the other, 'through the agency of asuitable means embodying lost motion connection, such as is common tothis art.

inasmuch as our invention pertains directly to the arcing terminals andhas no particular relation to the usual operating mechanism of thecircuit interrupter and other parts thereof which are essential to theconstruction of such a device, these parts are not illustrated ordescribed, it being believed `that our invention may be well understoodwithout illustration or description of these well-known parts.

Secured to the main contact member 2 and Yelectrically connectedtherewith is a supporting bracket 15 having a plurality of upwardlyprojecting arms' 16 between which one or more carbon arcing terminals 4are mounted. The arcing terminal 4 comprises a block of carbon or othersuitable material which is fastened rigidly to a member 17 by means ofbolts 18 and 19. The lower front .portion of the terminal 4 is recessedand adapted to receive the contactplate 6 which is secured in positionby' the bolt 19, the outer surface of the contact plate 6 and the carbonterminal 4 being in the same plane. The contact plate 6 is provided withan integral downwardly projecting extension 2O to which one end of a..flexible conducting member 21 is attached, the other end of said memberbeing fastened to the main contact member 2 in a manner that will behereinafter set forth. Thus a path of high electrical conductivity isprovided between the main contact member 3 and the tertiary contactplates 6.

The member 17 is provided with projecting side flanges 22, and a flangeQ3 disposed between them and at right angles thereto. The outer surfacesof the several side flanges 22 are provided with recesses 24 and withholes 25. The recesses Q4, justreferred to. are adapted to receive theupper ends of supporting links Q6 that are pivotally secured to theflanges Q2 by means of pins 27, which project through the holesQ. Thelower ends ofthe links 26 are pivotally Y mounted upon the supportingbracket 15,

through the agency of a rod 919 which projects through holes an saidlinks and in the arms 16. M

The arms 16 are provided with laterallyl and inwardly projecting lugs 30which are adapted to serve as stopsfor the links 26, and the forwardmovement of the carbon terminal 4 is also limited bytheengagement of thelinks 2.6 with the lower portions 31' of the recesses Z4, The backwardmovement of the links 26 and the contact terminal 4 is arrested by astrap 32 which is secured'to the arms 16 and extends the full width ofthe supporting bracket 15. Thus, the movement of the' links 26 and theterminals 4 is confined to prescribed limits, whereby the dcsiredoperation is insured.

One end of a resilient member 38 rests against the flange 23 of themember 17 and thereby maintains the arcingterminal 4 in engagement withits coperating contact member 5, as willbe readily understood. The otherend of the resilient member 33 is attached to a portion 34 of thebracket member`15. A plate 3i; isfastened to the front edges of thejnojectingarms 16 and serves to protect and inclosc the flexibleconductor 21 and the member 33.

The intermediate auxiliary contact terminal 10 is secured to the maincontact member 2 by means of'screws 36, and the lower end of theieziible conductor 21 is clamped between said terminal 10 and saidcontact member 2. l `urthermore, the contact terminal 10 is providedwith a Contact surface 37 that is inclined at a suitable angle to thevertical, for a purpose to be herein'- manner, to the main supportingstructure (not shown). The movable carbon contact terminal 5 is similarin construction to the contact terminal 4 and secured to the supportingarm 9 in much the same manner, by means of bolts 18 and 19, it beingunderstood that the terminal 5 is rigidly attached to the supporting arm9 and is not adapted for rotative movement. The contact plate 7 isassociated with the contact terminal in a manner similar to thathereinbefore described. and the plate 7 is electrically con nected tothe movable contact member 23, tlnough the agency of a flexibleconducting member 3S.

The contact terminal 11, which is adapted to coperate with thestationary contact terminal 10 is mounted upon the free end of aresilient member 39, the other end of which is rigidly attached to theclamping plate 14. It is essential to the desired operation of theinterrupter that the supporting member 39 be disposed in apj'noximatclythe same plane as the inclined contact surface 37 Iwhen the breaker isclosed. An adjusting screw 40 is provided ii'rtermediate the ends of theresilient member 39 and is adapted to rest against the movable member 3,whereby the resilient member 39 may be maintained under any desiredinitial tension, so that a considerable pressure is exerted between thecooperating contact .terminals 10 and 11 when engagement thereof iseffected.

Assuming that the various parts of the interrupter occupy the positionsshown in Figs. 1 and '2 and that the restraining means (not shown) ofthe interrupter is released, the operation is as follows: rlhesupporting arm 14 and its associated contact member move outwardly abouttheir pivotal support (not shown), thereby effecting the disengagementof the maincontact members Z and 3, it being understood that, as soon asthese members are separated, the current traversing the interrupterparts is carried by the several sets of auxiliary contact terminals.After the separation of the main contact members 2 and 3, theintermediate contact terminals 10 and 11 are disengaged, thereby causingthe contact plates 6 and 7 andthe cooperating .carbon contact terminals4 and 5 to carry all of the current.

lVhile the separation of the main contact members 2 and 3 and theintermediate contact terminals lO'and 11 is being effected, the enti-resurface of the carbon contact terminal 4 is maintained in engagementwith the cooperating surface of the carbon terminal 5 by means of thespring 33, which acts against the member 17. After contact terminals 1,0and 11 have become disengaged, the arm 9, acting through the connectingmeans (not shown) begins to move outwardly and allows the terminals 4and 6 to be, moved forward by the spring 33. During this operation, theterminals 4 and 5 ,and 6 and 7 are maintained in full engagementpuntilthe links 26 are rotated about their pivotal support 29, and themovement thereof is arrested by the stops 30. It will, of course, beunderstood that, on account of the linkage mechanism 8 to which thecarbon terminal 4 is secured, said terminal is slightly lowered inposition durimT the first portion of the opening operation, the parts4occupying the positions shown in Fig. 4 at a particular moment in theoperation. As the supporting arm 9 continues to move outwardly, thecarbon terminal 4 is given a rotative movement about its pivotalsupports 27, thereby causing said terminal to tilt for ward and effectseparation of the contact plates 6 and 7. Obviously, after theseparation of the plates 6 and 7, all of the current is carried by thecarbon terminals 4 and 5, which interpose a progressively increas-v ingresistance as the terminal 4 continues to tilt, thus preventingexcessive arcing at the moment of final interruption. The forwardrotative movement of the terminal 4 is limited by the engagement of theportions 31 of the recess 24 with the link 26, as already explained,

The structural details and the arrangement and location of parts, aswell as the relative proportions thereof, are so chosen that the severalsets of contact members and terminals are successively opened and,moreover, the main contact members 2 and 3 and the auxiliary contactterminals 10 and 11 and G and 7 are sui'liciently'r separated, prior tothe final disengagement of the carbon terminals 4 and 5, to prevent theformation of an are between them at the instant of final interruption.

rlhe positions of the various parts are shown in Fig. 5 just prior tothe disengagement of the carbon contact terminals 4 and 5. Subsequent tothe disengagement, thereof, the movable parts of the interrupter arecaused to be moved to their full. open positions, as will be readilyunderstood by those skilled in the art.

in closing the interrupter, the supporting arm 9 is moved inwardly, andthe circuit is first completed through the carbon contact terminals 4and 5 inthe manner shown in Fig. 5. s the supporting arm 9 continues tobe moved inwardly, the carbon contact terminal 4 is first given arotative movement about its pivotal supports 27, whereby the contactterminals 4 and 5 are caused to engage each other throughout theirentire contact surfaces, as shown in Fig. 4. As the closing operationproceeds further, the terminal 4 is forced inwardly against the spring33, andthe links 2G are caused to rotate rabout their pivotal support 29until said links are restricted in their movement by. reason of theirengagement with the member 32. ft will be understood that, as the finalstep in the closingA o eration is et'- fected, the contact terminal 4 ismoved up wai-illy, whereby a'sliding or wiping action is effectedbetween the terminal members 4 and 5. Thus, a good electrical contact'is obtai ned and the contact surfaces are cleaned and maintained ingood operating condition.

Prior to the final closure of the interrupter, the intermediate contactterminal 11 is brought into engagement with the inclined surface 37 ofthe stationary terminal 10 and, by reason of the initial tension in thespring 39, the adjust-ment of which has hereinbefore been explained, apositive and definite pressure is at once established between thecooperating intermediate terminals 10 and 11. After the initialengagement of the terminals 10 and 11 and din-ing the remainder of themovement of the arm 14 and its associated contact member 3, a slidingorwiping action is produced between said terminals as the terminal 11 ismoved upwardly along the inclined contact surface 37 of the terminal 10.As already explained, the resilient supporting member 39 for theterminal 1l is disposed in approximately the same plane as when thebreaker is closed, and, consequently, in case the contact surface isrough and defective, by reason of severe arcing, the mechanicalresistance to the n'iovement of the terminal 'l1 i-s exertedslibstantially in the plane of the member 39 .in the appended claims.

We Claim as our invention;

l. In a circuit interrupter, the Combination ivith relatively movableContact members, of a link for pivotally supporting one of the Contactmembers, and a stop adapted to be engaged on one side by the link tolimit its outward movement and adapted to be engaged on its other sideby a projection on the contact member to guide and limit its rotationalmovement.

2. In a lcircuit interrupter, the combination 'with relatively movablemain and auxiliary Contact members, of a doubly-pivoted supporting meansfor the auxiliary Contact member, anda single means for cooperating withthe supporting means for limiting its outward movement and forcooperating With fthe auxiliary contact member for limiting its rotativemovement.

3. In a circuit interrupter, the combination with relatively movablemain and auxilia'ry contact members, of a doubly-pivoted supportingmeans for the auxiliary Contact member, and a lug for engaging thesupporting means to limit its movement and for engaging the auxiliarycontact member `-to limit its yrotative movement.

Lineare 4. In a circuit interrupter, the Combination with relativelymovable main and auxiliary contact members, ot a rlouliily-pivotedsupporting` means ttor the auxiliarlgf contact member, and a lug forengaging the supporting means to limit its movement and for engaging aprojection on the auxiliary Contact member to limit its rotativemovement.

5. In al circuit interrupter, tliecon'ibination with relatiif'elymovable main and aux; iliary contact members, of a pair of links forpivotally supporting the auxiliary cont-ae member on a common axis,resilient means for maintaining the auxiliary Contact members inengagement when the interrupl'er is closed, and two lugs, the auxiliarycontact members being adapted to engage the lugs on one side and thelinks being adapted to engage the lugs on their other sides to limit therelative outward and rotative movements thereof, respectively.

6. In a circuit interrupter, the combination with relatively movablecontact members, of a link for pivotally supporting one oit' the contactmembers, a spring for maintaining the Contact members in engagement.when the circuit interrupter is closed, and a single means adapted tobe engaged on one side by the contact member and on the other side bythe link to limit the relative outward and rotative movements thereof,respectively.

In testimony whereof, we have hereunto subscribed our names this 25thday ot Sept.,

IGSEPII N. lwII-IONEY. VALTER M. AUSTIN. Witnesses:

M. C. lvlnnz, B. B. IIINns.

